1. Field of the Invention
The invention relates to a buffer. Particularly, the invention relates to a rail-to-rail current-mode interpolation buffer.
2. Description of Related Art
As a size and a resolution of a liquid crystal panel increase, a layout area of a display driving chip becomes larger. Therefore, it becomes an important issue to reduce the chip area and production cost.
Generally, a display capable of converting an image signal of N-bit resolution into an analog voltage may include 2N reference voltage traces to provide 2N gamma reference voltages, and a digital-to-analog converter therein switches to output one of the 2N gamma reference voltages to a voltage buffer according to the image signal.
However, as the resolution increases, the number of the reference voltage traces becomes larger, which lead to a considerable chip layout area.